Apparatus for redrawing and wall ironing containers



Nov. 18, 1969 J. 5. BOZEK 3,473,563

APPARATUS FOR REDRAWING AND WALL IRONING CONTAINERS Filed Nov. 27, 1967 I n L ,5 Ii I! I :54; i 5: i; 4| 471 J6 5o' r INVENTOR JOHN s. BOZEK BY I ML Anoxmsvs United States Patent US. Cl. 72-349 11 Claims ABSTRACT OF THE DISCLOSURE This disclosure is directed to an apparatus for redrawing and wall ironing cup-shaped metallic articles to produce containers or the like, and is particularly directed to a turret-like mechanism which at one station includes pneumatically actuated means for clamping a cup-shaped blank to a redraw die carried by a turret of the apparatus. The turret is indexed to bring the clamped article in alignment with a punch to one side of the turret and a plurality of wall ironing dies at an opposite side thereof. As the punch descends it is guided through the clamping means and progressively redraws and wall irons the cupshaped blank to a tubular container or similar articles.

It is conventional to form containers or similar tubular articles by first blanking circular discs from aluminum or similar metallic material. The circular discs are formed to a cup-shaped configuration either after or simultaneously with the blanking operation, and the cup-shaped blanks are thereafter redrawn and wall ironed by progressively forcing the blanks through a plurality of female redraw and wall ironing dies, generally by means of a reciprocating punch.

These conventional operations when performed separately or in various combinations are generally relatively slow despite the high speed of the punch press because of the necessity of employing multiple transfer devices between, for example, the blanking and cupping stations, the cupping and redrawing stations, etc.

There is on the other hand a similar deficiency in totally combining all of the latter-noted operations due to the slow speed of the press punch caused by the necessarily long stroke of the punch required to, for example, cup, redraw and wall iron a blank in a single operation.

Heretofore most attempts to produce commercially practical tubular articles have met with little success, particularly conventional mechanisms utilizing a 'long stroke press, because the speed of production was directly dependent upon the necessarily slow speed of the moving punch. If the redrawing and wall ironing operations were combined in a single step a cup-shaped blank was generally positioned atop a redraw die and the press actuated to move the punch in a direction forcing the blank through the redraw and succeeding wall ironing dies. During the necessary long stroke and slow movement of the punch no further operations are performed and thus the speed of production is directly dependent upon the speed of reciprocation of the press punch. Furthermore, difficulties have been continually encountered in maintaining each blank properly aligned relative to the dies and the punch axis which in many cases resulted in commercially unacceptable containers.

A primary object of this invention is, therefore, to avoid the above-noted and other disadvantages of conventional apparatuses by providing a novel redrawing and Wall ironing apparatus which includes means for clamping a cup-shaped blank at a first station of a turret mechanism during the redrawing and wall ironing of another cup- 3,478,563 Patented Nov. 18, 1969 "ice shaped blank at a second station whereby the time between forming successive articles is dependent solely upon the speed of indexing a clamped article to the punching station, thereby materially increasing the speed of production as compared to conventional machines.

A further object of this invention is to provide a novel redrawing and wall ironing apparatus wherein a plurality of redraw dies and clamping means are carried by a turret whereas but a single set of wall ironing dies are positioned immovably at the punching station, thereby reducing the cost normally associated with conventional apparatuses in which each redraw die is associated with an individual set of wall ironing dies.

Still a further object of this invention is to provide a novel apparatus of the type heretofore set forth wherein the clamping means additionally includes means for accurately alinging each cup-shaped blank with its axis in alignment with the axes of the redraw and wall ironing dies, and means are further provided in conjunction with each clamping means for guiding the press punch during its working stroke.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claimed subject matter, and the several views illustrated in the accompanying drawing.

In the drawing:

FIGURE 1 is a highly schematic top plan view of a novel apparatus for redrawing and wall ironing cup- .shaped blanks in accordance with this invention, and illustrates a plurality of redraw dies carried by a turret movable between a loading station and a forming station.

FIGURE 2 is an enlarged side elevational view partly in section of the apparatus of FIGURE 1, and more clearly illustrates the manner in which each cup-shaped blank is clamped to an associated redraw die at a first station during which time a previously clamped blank is redrawn and wall ironed.

An apparatus for redrawing and wall ironing cupshaped blanks B is schematically illustrated in FIGURE 1 of the drawing, and is generally designated by the reference numeral 5. The apparatus 5 includes a conveying mechanism or turret 6 which is rotated in a clockwise direction as viewed in FIGURE 1 by a conventional indexing mechanism 7. The turret 6 is indexed from a loading station 8 to a dwell station 9 and then to a forming and unloading station 10.

Reference is now made to FIGURE 2 of the drawing which illustrates theapparatus 5 as including a support 11 forming a base for the turret 6. The turret 6 includes a platform 12 secured to a member 13 mounted for rotation upon a post 14 in a conventional manner. The member 13 carries a sprocket 15 about which is entrained a. drive chain 16. The chain 16 is turn entrained about a drive sprocket 17 of the indexing mechanism 7, as shown in FIGURE 1. Thus, upon the rotation of the sprocket 17 in a clockwise direction the platform 12 is rotated in a similar direction through the chain 16 and the sprocket 15.

A plurality of circular pockets 18 are formed in the platform 12 at 12 oclock, 3 oclock, 6 oclock and 9 oclock (FIGURE 1). Each pocket 18 receives a flanged redraw die 20 having an annular inner surface 21 complementarily contoured to an outer surface portion (unnumbered) of the cup-shaped blanks B. The surface 21 terminates at a cylindrical bore 22.

Clamping means 25 are also associated with each of the redraw dies 20 to accurately position each blank B within its associated redraw die 20. The clamping means 25 are identical and each includes a generally tubular clamping body 26 having a flange 27 at diametrically opposite sides of which are secured piston rods 28, 30. The rods 28, 30 pass through sealed bores (unnumbered) formed in the platform 12 and are received in cylinders 31, 32, respectively. In the unclamped or upper position of the clamping body 26 each piston 33, 34 associated with the respective cylinders 31, 32 is urged to an uppermost position by a fluid medium introduced into the respective cylinders 31, 32 from a source of high pressure, such as compressed air, through conduits 35, 36 in a manner readily apparent from FIGURE 2 of the drawing. Valves (not shown) are preferably arranged in the conduits 35, 36 such that the conduits 35, 36 can be vented to atmosphere at the same time that conduits 38 are placed in fluid communication with the same source of high pressure fluid. The high pressure fluid in the conduits 38 is conducted into the cylinders 31, 32 above the pistons 33, 34 via conduits 40, 41 to urge the pistons 33, 34 and the associated rods 28, 30 in a downward direction thus firmly clamping each blank B to its associated redraw die 20, in the manner clearly illustrated in the right-hand portion of FIGURE 2. It is to be particularly noted that in the clamped position an outer annular surface portion 42 of the tubular body 26 matingly engages an inner surface (unnumbered) of the blank B thus accurately aligning the axis of the latter with the axis of its associated redraw bore 22 and an inner cylindrical surface 43 which forms a guide for a punch 44 of a conventional punch press 45.

Conventional means (not shown) are provided for opening each clamping mechanism 25 just prior to ap preaching the loading station 8 at which time conventional conveying and feeding means 46 deposit each of the blanks B in an associated one of the redraw dies 20. Thereafter the clamping mechanism 25 is actuated to its closed position in the manner heretofore described prior to reaching the forming station 10.

At the forming station the turret 6 is indexed to and stopped at a position at which the axis of the associated redraw die is in alignment with the axis of the punch 44 and the axes of a plurality of female wall ironing dies 47, 48 supported by a generally tubular column 50 having a side discharge opening 51. Though only a pair of wall ironing dies 47, 48 are illustrated in FIGURE 2, it is to be understood that more or less than this number may be provided with the diameters thereof progressively decreasing in size in a downward direction to effect the wall ironing of each blank B after being redrawn through the bore 22 of each die 20 in a conventional manner to form a tubular container or similar cupshaped article C. The container C may be additionally bottom-paneled if desired by providing the punch 44 with a downwardly opening concave end face 52 corresponding in configuration to a bottom paneling die 53 such that upon the punch 44 reaching the bottom of its stroke the complementary surfaces of the elements 52, 53 bottompanel each container C in a conventional manner.

After each forming operation the punch 44 is retracted and the indexing mechanism 7 actuates to continue the rotation of the turret 6, it being noted that the post 50 is provided with anti-friction bearing means 54 in the form of a plurality of roller bearings engaging the lower surface of the platform 12. The bearings 54 thereby not only faciliate the rotation of the platform 12 relative to the post 50, but also lend support to the platform 12 against the downward force of the punch 44 during each forming operation.

During the retraction of the punch 44 each redrawn and wall ironed container C can, of course, be discharged by suitable conventional means (not shown) outwardly of the discharge opening 51 to a conventional storage or finishing area via a chute 55.

It is also to be particularly noted that as soon as the punch 44 has been retracted to its home position a cupshaped blank at the dwell station 9 is at a position to be immediately indexed to the forming station 10 by the turret 6 while at the same time the clamping mechanism 25 at the station at 6 oclock can be opened prior to being indexed to the loading station 8. Thus, the sole criterion for the speed at which the blanks B are redrawn and wall ironed is the speed at which the punch 44 can be descended and retracted, it being noted that at all times clamped blanks are available for immediate positioning at the forming station 10 dependent solely upon the speed required for moving the turret 6 from the station 9 to the station 10. It should also be noted that the pre-blanking and pre-cupping of the blanks B also reduces the stroke of the punch 44 thus automatically increasing the speed of operation of the apparatus 5 as compared to, for example, performing a cupping operation at the forming station 10 in addition to redrawing and wall ironing.

While preferred forms and arrangement of parts have been shown in illustrating the invention, it is to be clearly understood that various changes in details and arrangement of parts may be made without departing from the spirit and scope of the invention as defined in the appended claimed subject matter.

I claim:

1. Apparatus for redrawing and wall ironing cup-shaped blanks comprising a conveying mechanism, a plurality of redraw dies carried by said conveying mechanism, at least a pair of stations disposed along the path of travel of the conveying mechanism and the redraw dies carried thereby, means at a first of said stations for positioning a cup-shaped blank relative to an associated one of said redraw dies, means at a second of said stations for forcing each cup-shaped blank through its associated redraw die, and at least an additional female die at said second station through which each cup-shaped article is progressively urged by said forcing means.

2. The apparatus as defined in claim 1 wherein said additional female die is immovably positioned at said second station.

3. The apparatus as defined in claim 1 wherein said positioning means includes means for clamping each cupshaped article to an associated redraw die.

4. The apparatus as defined in claim 1 wherein said additional female die is immovably positioned at said second station, and anti-friction means are positioned between said conveying mechanism and said additional female ie for freely movably supporting said conveying mechanism relative thereto.

5. The apparatus as defined in claim 1 wherein said positioning means includes means for clamping each cupshaped article to an associated redraw die, said clamping means being pneumatically operated, each clamping means being defined by a generally tubular clamping body having inner and outer surface portions complementarily contoured to the outer surface portions of the forcing means and to the inner surface portion of the cup-shaped blanks respectively, and means for indexing said conveying mechanism to bring axes of the clamping body surface portions into axial alignment with said forcing means and said additional female die.

6. The apparatus as defined in claim 2 wherein said positioning means includes means for clamping each cupshaped article to an associated redraw die.

7. The apparatus as defined in claim 2 wherein said additional female die is immovably positioned at said second station, and anti-friction means are positioned between said conveying mechanism and said additional female die for freely movably supporting said conveying mechanism relative thereto.

8. The apparatus as defined in claim 2 wherein said positioning means includes means for clamping each cupshaped article to an associated redraw die, said clamping means being pneumatically operated, each clamping means being defined by a generally tubular clamping body having inner and outer surface portions complementarily contoured to the outer surface portions of the cup-shaped blanks respectively, and means for indexing said conveying mechanism to bring axes of the clamping body surface portions into axial alignment With said forcing means and said additional female die.

9. The apparatus as defiined in claim 3 wherein said additional female die is immovably positioned at said second station, and anti-friction means are positioned between said conveying mechanism and said additional female die for freely movably supporting said conveying mechanism relative thereto.

10. The apparatus as defined in claim 3 wherein said positioning means includes means for clamping each cupshaped article to an associated redraw die, said clamping means being pneumatically operated, each clamping means being defined by a generally tubular clamping body having inner and outer surface portions complementarily contoured to the outer surface portions of the cup-shaped blanks respectively, and means for indexing said conveying mechanism to bring axes of the clamping body surface portions into axial alignment with said forcing means and said additional female die.

11. The apparatus as defined in claim 4 wherein said positioning means includes means for clamping each cupshaped article to an associated redraw die, said clamping means being pneumatically operated, each clamping means being defined by a generally tubular clamping body having inner and outer surface portions complementarily contoured to the outer surface portions of the cup-shaped blanks respectively, and means for indexing said conveying mechanism to bring axes of the clamping body surface portions into axial alignment with said forcing means and said additional female die.

References Cited UNITED STATES PATENTS 2,183,287 12/ 1939 Candee 72-405 3,289,453 12/1966 Wyle et al 72-349 RICHARD J. HERBST, Primary Examiner US. Cl. X.R. 72361; 405; 421 

